i. 218;

on the number of species of man, i. 226; on the courtship of the land-snails, i. 324; on the brightness of the colours of male fishes during the breeding season, ii. 13; on the frontal protuberance of the males of _Geophagus_ and _Cichla_, ii. 13, 20; on the slight sexual differences of the South Americans, ii. 323; on the tattooing of the Amazonian Indians, ii. 342.

AGE, in relation to the transmission of characters in birds, ii. 183; variation in accordance with, in birds, ii. 213.

_Agelaeus phoeniceus_, ii. 116.

_Ageronia feronia_, noise produced by, i. 387.

_Agrion_, dimorphism in, i. 363.

_Agrion Ramburii_, sexes of, i. 362.

AGRIONIDAE, difference in the sexes of, i. 362.

_Agrotis exclamationis_, i. 369.

AGUE, tertian, dog suffering from, i. 13.

_Aithurus polytmus_, young of, ii. 220.

AINOS, hairiness of the, ii. 321.

_Alca torda_, young of, ii. 217.

_Alces palmata_, ii. 259.

ALDER and Hancock, MM., on the nudibranch mollusca, i. 326.

ALGEN, Mr., on the stridulation of _Scolytus_, i. 379.

ALLEN, J. A., on the relative size of the sexes of _Callorhinus ursinus_, ii. 260; on the mane of _Otaria jubata_, ii. 267; on the pairing of seals, ii. 279; on sexual differences in the colour of bats, ii. 286.

ALLEN, S., on the habits of _Hoplopterus_, ii. 48; on the plumes of herons, ii. 82; on the vernal moult of _Herodias bubulcus_, ii. 84.

ALLIGATOR, courtship of the male, i. 272, ii. 29; roaring of the male, i. 331.

AMADAVAT, pugnacity of male, ii. 49.

_Amadina Lathami_, display of plumage by the male, ii. 95.

_Amadina castanotis_, display of plumage by the male, ii. 95.

AMAZONS, butterflies of the, i. 309; fishes of the, ii. 17.

AMERICA, variation in the skulls of aborigines of, i. 108; wide range of aborigines of, i. 218; lice of the natives of, i. 220; general beardlessness of the natives of, ii. 322.

AMERICA, North, butterflies of, i. 309; Indians of, women a cause of strife among the, ii. 324; Indians of, their notions of female beauty, ii. 344, 347.

AMERICA, South, character of the natives of, i. 216; population of parts of, i. 225; piles of stones in, i. 233; extinction of the fossil horse of, i. 239; desert-birds of, ii. 224; slight sexual difference of the aborigines of, ii. 323; prevalence of infanticide in, ii. 361.

AMERICAN languages, often highly artificial, i. 112.

AMERICANS, wide geographical range of, i. 112; and negroes, difference of, i. 247; aversion of, to hair on the face, ii. 348; native, variability of, i. 226.

_Ammophila_, on the jaws of, i. 342.

_Ammotragus tragelaphus_, hairy forelegs of, ii. 282, 285.

AMPHIBIA, affinity of, to the ganoid fishes, i. 204; vocal organs of the, ii. 331.

AMPHIBIANS, i. 213, ii. 24; breeding whilst immature, ii. 215.

_Amphioxus_, i. 204.

AMPHIPODA, males sexually mature while young, ii. 215.

AMUNOPH III., negro character of features of, i. 217.

ANAL appendages of insects, i. 342.

ANALOGOUS variation in the plumage of birds, ii. 74.

_Anas_, ii. 180.

_Anas acuta_, male plumage of, ii. 84.

_Anas boschas_, male plumage of, ii. 84.

_Anas histrionica_, ii. 214.

_Anastomus oscitans_, sexes and young of, ii. 217; white nuptial plumage of, ii. 228.

ANATIDAE, voices of, ii. 60.

_Anax junius_, difference in the sexes of, i. 362.

ANGLO-SAXONS, estimation of the beard among the, ii. 349.

ANIMALS, cruelty of savages to, i. 94; domesticated, more fertile than wild, i. 132; characters common to man and, i. 185; domestic, change of breeds of, ii. 369.

ANNELIDA, i. 327.

ANNULOSA, i. 327.

_Anolis cristatellus_, male, crest of, ii. 32; pugnacity of the male, ii. 32; throat-pouch of, ii. 33.

_Anobium tessellatum_, sounds produced by, i. 384.

_Anser canadensis_, ii. 116.

_Anser cygnoides_, ii. 114; knob at the base of the beak of, ii. 129.

_Anser hyperboreus_, whiteness of, ii. 228.

ANTELOPE, prong-horned, horns of, i. 289.

ANTELOPES, generally polygamous, i. 267; horns of, i. 289, ii. 245; canine teeth of some male, ii. 241; use of horns of, ii. 251; dorsal crests in, ii. 282; dewlaps of, ii. 284; winter change of two species of, ii. 299; peculiar markings of, ii. 299.

ANTENNAE, furnished with cushions in the male of _Penthe_, i. 343.

_Anthidium manicatum_, large male of, i. 347.

_Anthocharis cardamines_, i. 388, 393, 394; sexual difference of colour in, i. 409.

_Anthocharis genutia_, i. 393.

_Anthocharis sara_, i. 393.

_Anthophora acervorum_, large male of, i. 347.

_Anthophora retusa_, difference of the sexes in, i. 366.

_Anthus_, moulting of, ii. 83.

ANTHROPIDAE, i. 195.

ANTIGUA, Dr. Nicholson's observations on yellow fever in, i. 245.

ANTICS of birds, ii. 68.

_Antilocapra americana_, horns of, i. 289, ii. 245.

_Antilope bezoartica_, horned females of, ii. 246, 248; sexual difference in the colour of, ii. 288.

_Antilope Dorcas_ and _euchore_, ii. 245.

_Antilope euchore_, horns of, ii. 251.

_Antilope montana_, rudimentary canines in the young male of, ii. 258.

_Antilope niger, sing-sing, caama_, and _gorgon_, sexual differences in the colours of, ii. 289.

_Antilope oreas_, horns of, i. 289.

_Antilope saiga_, polygamous habits of, i. 267.

_Antilope strepsiceros_, horns of, i. 289.

_Antilope subgutturosa_, absence of suborbital pits in, ii. 280.

ANTIPATHY, shown by birds in confinement, to certain persons, ii. 110.

ANTS, i. 186; playing together, i. 39; memory in, i. 45; intercommunication of, by means of the antennae, i. 58; large size of the cerebral ganglia in, i. 145; soldier-, large jaws of, i. 155; difference of the sexes in, i. 365; recognition of each other by, after separation, i. 365.

ANTS, White, habits of, i. 364.

ANURA, ii. 25.

_Apatania muliebris_, male unknown, i. 314.

_Apathus_, difference of the sexes in, i. 366.

_Apatura Iris_, i. 386, 388.

APES, anthropomorphous, i. 196; difference of the young, from the adult, i. 13; building platforms, i. 53; probable speedy extermination of the, i. 201; Gratiolet on the evolution of, i. 230; semi-erect attitude of some, i. 142; mastoid processes of, i. 143; influence of the jaw-muscles on the physiognomy of, i. 144; female, destitute of large canines, i. 156; imitative faculties of, i. 161; canine teeth of male, ii. 241; females of some, less hairy beneath than the males, ii. 377.

APES, long-armed, their mode of progression, i. 143.

_Apis mellifica_, large male of, i. 347.

APOLLO, Greek statues of, ii. 350.

APOPLEXY in _Cebus Azarae_, i. 12.

APPROBATION, influence of the love of, i. 86, 92, 164, 165.

APPENDAGES, anal, of insects, i. 342.

_Aprosmictus scapulatus_, ii. 174.

AQUATIC birds, frequency of white plumage in, ii. 229.

_Aquila chrysaetos_, ii. 105.

ARAB women, elaborate and peculiar coiffure of, ii. 353.

ARABS, gashing of cheeks and temples among the, ii. 339.

ARACHNIDA, i. 337.

ARAKHAN, artificial widening of the forehead by the natives of, ii. 351.

_Arboricola_, young of, ii. 190.

_Archeopteryx_, i. 204.

ARCTIIDAE, coloration of the, i. 396.

_Ardea asha_, _rufescens_, and _caerulea_, change of colour in, ii. 231, 232.

_Ardea caerulea_, breeding in immature plumage, ii. 214.

_Ardea gularis_, change of plumage in, ii. 232.

_Ardea herodias_, love-gestures of the male, ii. 68.

_Ardea ludoviciana_, age of mature plumage in, ii. 213; continued growth of crest and plumes in the male of, ii. 216.

_Ardea nycticorax_, cries of, ii. 51.

_Ardeola_, young of, ii. 190.

_Ardetta_, changes of plumage in, ii. 179.

ARGENTEUIL, i. 29.

ARGUS pheasant, ii. 72, 97, 181; display of plumage by the male, ii. 91; ocellated spots of the, ii. 134, 141; gradation of characters in the, ii. 141.

ARGYLL, Duke of, the fashioning of implements peculiar to man,